Swiss Arms SG 553 R (7.62x39)

[KTR03]

These were the 31 paid on full guns. The rest arrive in late January.

[Bret]

OK. Please post detailed pictures when it arrives and do a reliability test too.

[KTR03]

OK. Please post detailed pictures when it arrives and do a reliability test too.

My plan is to get it engraved, do the work to make it an sbr, (I have my stamp) put a rediculous scope on it and test accuracy with federal fusion, whatever generic x39 I have lying around, and then scratch up some 8m3. Then I will rescope it with a 1.25 -4 leupold and run some drills. Also will run it with an sdn6 and see how it goes. It is sitting at my ffl in WA and I am I Denver.

[Bret]

After over a two year wait, I finally have my San Swiss Arms 553RP. Here it is below my Sig 556 SBR.


Field stripped.


Here's the barreled action of the 553RP versus the 556 SBR. Note that the gas system of the 553RP is slightly shorter.


As a result, the gas piston of the 553RP is slightly shorter.


The trigger groups from each rifle appear to be virtually identical. I'm hoping that they'll interchange which would give me three easy 922r parts. The pin diameters are the same.

[Bret]

I took it to the range today along with 110rds of Wolf 123gr FMJ Copper Jacket that was made in a Ukrainian factory that the Russians destroyed. I loaded the ammunition in (2) Magpul Gen3 30rd mags, a Hungarian 20rd mag and an Eastern Block 30rd metal magazine of unknown origin. I've used the Hungarian and Eastern Block magazines previously with no issues. The Magpul Gen3 mags were a bear to get locked in place. Once locked in place, it was difficult to retract the carrier to the rear. However, once I did that, they did cycle just fine. They were also a bear to unlock. The Hungarian and Eastern Block mags inserted easily, the carrier retracted easily with them in place and they were easy to unlock.

Now for the sort of bad news. I had (7) failures to fire. Looking at the primers, it appears that they were hit hard enough, but just didn't ignite. Now I might be worried about this, but I've been down this route before with my Windham Weaponry 7.62x39 AR-15. It would fail to ignite the primers of this same ammo occasionally too, but they would always fire on the second strike. I didn't retry when this happened in the 553RP. The Windham would run 100% with Lapua 123gr FMJ and IMI 123gr FMJ. After I installed a Wolff extra power AR-15 hammer spring in the Windham, it runs 100% when running this Wolf 123gr FMJ Copper Jacket. So, lesson learned. These primers are kind of hard to ignite.

Now for the thing that concerns me. I had two failures to feed when using the Eastern block magazine. Both times the bullet ended up hitting above the chamber which made the cartridge stop at about a 45deg angle.

When I got home I grabbed an assortment of AK magazines. All would lock and unlock easily except the Magpul Gen3's and Bulgarian waffles. Interestingly, the Magpul Gen1 that came with the pistol locked in and unlocked just fine. Perhaps I was overthinking it going with the Gen3 version because they have the metal insert at the top. I took a file to the underside of the mag catch of the two Gen3's. It took a while, but they now lock in pretty easily. They still take a little force to unlock, but I didn't want to push my luck.

My plan when I go to the range tomorrow is to see if I get light primer strikes with other ammo. I also need to see if I have any feeing issues when just using the Gen3 Magpuls. I'm taking some Golden Tiger 123gr FMJ bimetal to try out initially. If it works fine, then I'll know that the Wolf ammo I tried just has hard primers. If I still get failures to ignite, then I'll give it a go with some Lapua 123gr FMJ.

[Bret]

I had better results at the range today. I fired 85rds of Golden Tiger 123gr FMJ bimetal using the two Gen3 Magpul magazines. All fired and cycled successfully. I'm going to purchase some new Wolf Polyformance 125gr FMJ copper jacket to see how it performs. Brass cased 7.62x39 is very expensive, but I'd rather not shoot the bimetal jacketed ammo through the 553RP.

[Bret]

Today I fired 120rds of the aforementioned Wolf Polyformance 125gr FMJ copper jacket through the 553RP. Function was 100%. I ran the 1st through with the gas regulator set to 14. It was tossing brass about ten yards. For the 2nd, 3rd and 4th magazines, I set the gas regulator to 13. Most cases went about five yards on average. I didn't try setting it to 12 because I figured that would be pushing my luck too far. Now to fill out that Form 1.

[MadAngler1]

Did you finally get the gen 3 magpul mags to work? Since US Palm is now bankrupt, whom else makes quality AK mags? Does Arsenal have US made mags? Nothing beats Bulgarian waffles and Russian mags for AK 47 and 74 pattern rifles IMHO. It seems that non-Bulgarian and Russian AKs tend to have different tastes when it comes to polymer AK mags.

Just to clarify, I am referring to polymer mags. Old steel eastern block mags run great as well

[Bret]

I did get the Magpuls to work, but it took some filing on the catch tabs. Arsenal has mags with US followers and floor plates. That would be a better alternative, but you'd have to use another US compliance part somewhere else. My US compliance parts are:
FCG = 3
Magazine = 3
Flash hider = 1

As far as I know, there are not any other US parts that can be used, but I'm open to ideas.

[Bret]

I was finally able to complete my 553R SBR. I swapped out the factory trigger group with a ShootingSight hammer and sear along with a Sig USA trigger. Dry firing it definitely feels better than the factory trigger group, but I'll have to see how it feels at the range. Dave confirmed that the threading of the muzzle is 5/8x24RH. I was able to remove the factory flash hider, so now I'm looking to find something to replace it. I'm thinking about installing some sort of 3-lug adapter & flash hider combination. Suggestions are welcome. I know that many don't care about sec922(r), but the rifle is now compliant using the Magpul magazines.